<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>3CSS常用值</title>
    <style>
        h1{
            /*color:red;*/
            /*color: rgb(255,0,0);*/
            /*color: rgb(0,255,0);*/
            /*color: rgb(0,0,255);*/
            /*color: #ff0000;*/
            /*color: #00ff00;*/
            /*color: #0f0;*/
            /*color: #000000;*/
            /*color: #000;*/
            /*不透明度 alpha*/
            color: rgba(0,0,255,1);
            /*color: rgba(0,0,255,0.8);*/
            /*color: rgba(0,0,255,0.5);*/
            /*color: rgba(0,0,255,.3);*/
            /*color: rgba(0,0,255,0);*/

        }
        .d1{
            background-image: url("img/mr.png");
            width: 150px;
            height: 100px;
            background-size: 50px 100px;
            background-color: cyan;
        }
        .d2{
            width: 300px;
            height: 300px;
            border: 5px solid #f00;
            background-image: url("img/mr.png");
            background-repeat: no-repeat;
            /*background-position: right bottom;*/
            /*background-position: 50px 0;*/
            background-position: 100% 100%;

        }
        .d4{
            width: 611px;
            height: 376px;
            background-color: #e8e8e8;
            background-image: url("img/computer1.png");
            background-size: 318px 319px;
            background-repeat: no-repeat;
            background-position: 90% 60%;
        }
    </style>
</head>
<body>
    <h1>测试颜色</h1>
    <div class="d1"></div>
    <div class="d2"></div>
    <div class="d4"></div>
    <div class="d3">
        <div class="text">
            <h1>我是标题</h1>
        </div>
    </div>
</body>
</html>